Field-magnet for dynamo-electric machines or electric motors.



N0. 695,l63. Patented Mar. ll, I902. R. LUNDELL.

FIELD MAGNET FOR DYNAMO ELECTRIC MACHINES 0R ELECTRIC MOTORS.

(Application filed Dec. 18, 1901.)

(N0 Mo 2 Sheets-$heet I.

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N0. 695,I63. Patented Mar. II, I902. R. LUNDELL. FIELD MAGNET FOR DYNAMOELECTRIC MACHINES 0R ELECTRIC MOTORS.

(Apphcatiou filed Dec. 18. 1901.) (No Model.) 2 Sheets-$heet 2.

IIIII-IIIIII Q VL'IMQQ o I @wam JEM Lid /J UNITED STATES PATENT OFFICE.

ROBERT LUNDELL, OF NEV YORK, N. Y.

FIELD-MAGNET FOR DY NAMO-ELECTRIC MACHINES OR ELECTRIC MOTORS.

QPEGIFIGATION forming part of Letters Patent N 0. 695,163, dated March11, 1902.

Application filed December 18, 1901. Serial No. 86,896. (No model) To(0Z7, whom II /5 71mg concern- Be itknown that l, ROBERT LUNDELL,acuizen of the United States, residing at New York, borough ofManhattan, county and State of New York, have invented certain new anduseful Improvements in Field-Magnets for Dynamo-Electric Machines orElectric Motors, of which the following is a specification.

Thesaid improvements pertain to a class of fieldnnagnets known aslaminated fieldmagnets, and they are applicable to various classes ofdynamo-electric machines, but particularly to motors used forrailway-service.

The chief object of my invention is to provide efficient means forsupporting a body of segmental laminated iron forming the outer magneticcircuit of a dynamo-electric machine or motor in an absolutely rigidmanner without increasing the dimensions which limit the height andwidth of the apparatus.

It is well known in the art that laminated field-magnets are superior tosolid field-magnets in many respects. For instance, they insure uniformcross-sections in the various magnetic circuits and great uniformity ina line of duplicate machines, which is of utmost importance when severalmachines are arranged to run in parallel. They also make quick changesin the magnetic flux possible.

I am aware that it is old in the art to support a laminated field-magnetby solid castings surrounding the same; but I know of no constructionwhich could successfully be applied to streetcar or railway motors,which must be crowded into the small space available on modern trucks.

To fully describe my invention, I will refer to the accompanying twosheets of drawings, in which- Figure 1 is a vertical section, taken atline a; cc of Fig. 2, of the laminated field-magnet with itssupporting-frame; and Fig. 2 is a plan View of the same. Fig. 3 is anend view of one of the supporting-brackets; and Fig. 4: is a section ofthe completed field-magnet, taken at line y y of Fig. 2.

Referring now to the drawings in detail and particularly to Fig. 1, L, LL and L represent four sheet-iron punchings, each a duplicate of theother. They are of such form that when turned around for every alternatelayer they will overlap or dovetail at the four corners, as clearlyindicated on the drawings by the dotted lines. Thesmall steel rods R, RR and R, which pass through punched holes in the overlapping sections,serve to lock the four sections together, and the other rods R R B &c.,to R will keep the surface of the laminations absolutely smooth as thepunchings are assembled, so that the poles may be bolted onto thecompleted yoke without extra finish. The laminations are assembled inone of the brackets A or A (See Fig. 2.) Each of said brackets has fourstrong arms or projections, constituting connecting-pieces, of which 0,C C and O belong to bracket A and D D &c., to bracket A These bracketsare preferably made of east-steel. Heavy bolts B, B B and B (see Figs. 1and 2) pass through said arms, locking one bracket to the other, thuscompleting a skeleton frame, which is preferably rigid with or withoutthe laminated body portion. Both brackets are furnished with small holes(drilled from a templet) to receive the ends of the steel rods R B &c.,to R which run from one bracket to the other through the entirelaminated body. The laminated body can be built up, using either bracketas a foundation. The twelve steel rods or pins are inserted in theirrespective holes, and the laminations are threaded on the pins in theusual manner. The four corner-arms of the bracket will serve to centerthe laminations. A sufficient number of punchings are assembled on thepins to insure a perfectly tight body when the other bracket is bolteddown against the first one.

It will be seen on inspection of Figs. 1 and 2 that the four arms orconnecting-pieces C 0 &c,, D D &e., are so located relatively to thelaminated body portions L, L L and L that they do not increase theheight or widththat is to say, the exterior limiting dimensions-dintallow the laminations to protrude or project between said arms to theextreme outer faces of the machine.

Fig. 3 shows one of the box-shaped brackets in detail. The large openingin the same centers a bracket containing one of the armature-bearings.(Not shown on the drawings.)

Fig. a serves to explain the previous views and shows in particular therelative thick ness of metal in the box-shaped brackets as compared tothe magnetic circuits. This view illustrates also the manner in whichthe laminated poles P, P P and P are secured to the laminated yoke.

My invention contemplates, broadly, the construction of adynamo-electric machine or electric motor having a laminated fieldmagnetin which the laminations are held together en masse by end brackets orsupports and bolts, arms or projections being combined therewith andlocated at the corners of the brackets or supports for rendering thestructure rigid, the entire arrangement being such that the laminationsextend outward between the outer or lateral edges of the brackets orsupports, the united edges of the massed laminations constituting, ineffect, the outer faces of the machine, thereby avoiding the presence ofany useless metal between the outer edges of the laminations and anysurface beneath, beside, or over which the machine may be secured, thusmaterially economizing space, a motor with such a fieldmagnet havingespecial utility in connection with tram-cars and in similar placeswhere the space isnecessarily limited.

Having thus described my invention, what I claim, and desire to secureby Letters Patent of the United States, is

1. A laminated field-magnet inclosed or outer edges projecting betweenthe support-j ing parts of the frame.

5. A flattened form of laminated field-magnet supported by two endbrackets having connecting-pieces across the laminated body portion; incombination with bolts through said connecting-pieces, substantially asdescribed.

In testimony whereof I have signed my name to this specification in thetwo subscribing witnesses.

ROBERT LUNDELL.

WVitnesses:

O. J. KINTNER, M. F. KEATING.

presence of

